Update README changelog
Fix docblocks
Explicitly show includes in examples
Provide twi_is_enabled()

- Also remove unnecessary error checking
- Explicitly define TWI pins as OPENDRAIN in the twi example
Add hd44780 scroll text example
Declare built-in functions via extern keyword

- Read here why to do this,
  https://github.com/quarnster/SublimeClang/issues/134
Cast ADC_VREF to double (be specific)

- http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&p=998242#998242
Fix `aery::pwm_update_dutycl()`. Closes gh-11.

-Now handles the division by zero gracefully
Fix changelog

- The previous commit should have stated fixing gh-13.
Improve the gpio_init()

- Glitch filter should only be changed when IER is zero.
Add new example: external interrupt on pin change
Update external interrupt pin change example
Improve comments in the external interrupt pin change example
Fix (workaround) to reset TWI RXRDY flag

- See errata, datasheet p. 794
Implement functions which operate with the flash user page
Fix aery::flashc_write_fusebit()
Add functions to read fuse bits and write fuse bytes
Fix README
Fix README
Fix flashc_write_fusebyte()